1. EMBRYO TRANSFER Dr. M. Hakan ÖZÖRNEK EUROFERTIL
Reproductive Health Center
Istanbul, Turkey

2. Variables affecting pregnancy rates
Uterine receptivity
Embryo quality
Transfer efficiency

3. ET is the final and most crucial step in IVF
ET technique has been given little attention and the published data on the subject are minimal.
But it is not as simple as it looks

4. Variables affecting ET success
Trial transfer
Cervical mucus
Catheter typ
Difficult ET
Ultrasound quidance

5. Embryo transfer

6. Significant differences were observed in pregnancy rates after the embryo transfer was performed by different clinicians
Hearn-Stokes, et al., Fertil Steril, 2000

7. Trial transfer
A trial transfer in a cycle preceding IVF for the purpose of measuring the uterine cavity depth and direction apperars to be of value.

8. Trial transfer 335 patients Pregnancy rates Trial group 22.8%
No trial group 13.1%
Mansour, et al., Hum Reprod, 1994

9. Trial transfer
Because of the great variability in cervical and uterine anatomy a trial transfer is beneficial.

10. Cervical mucus Mucus plugging of the catheter tip can cause
Retained embryos
Damage to the embryos
Improper embryo placement

11. Cervical mucus Cervical lavage before ET to remove all visible mucus
55% pregnancy rate with lavage
41% pregnancy rate without lavage
Mac Namee

12. Cervical mucus
Embryos may be retained in the catheter owing to plugging of the tip with mucus or uterine tissue.
Visser (1993) found a decrease in pregnancy rates from 20% to 3% when embryos were retained.

13. Cervical mucus Cervical mucus can plug the tip of the catheter
The embryos can stick to the cervical mucus around the catheter and be dragged outside during the withdrawal of the catheter.

14. Cervical mucus
In a retrospective study analysing 1204 embryo transfer procedures, it was shown that the embryos were much more likely to be retained when the embryo transfer catheter was contaminated with mucus or blood.
Nabi, et al., Hum Reprod, 1997

15. Catheters
The ideal embryo transfer catheter should be soft enough to avoid any trauma to the endocervix or endometrium and malleable enough to find its way into the uterine cavity

16. Catheter type
Although stiff catheters and use of a rigid outer sheath make catheter placement easier, they may result in more bleeding, trauma, mucus plugging and stimulation of uterine contractions.

17. Catheter type
Soft catheters allow the tip to follow the contour of the cervical and uterine axis and minimize trauma to the endometrium.

18. Catheter type Pregnancy rate with different catheters Frydman 32%
Wallace 19%
TDT 19%
Wisanto, et al., Fertil Steril, 1989

19. Catheter type Pregnancy rate with different catheters 518 IVF cycles
Frydman 31%
Wallace 30%
Al-shawaf, et al., J Assist Reprod Genet, 1993
518 IVF cycles
Soft catheter 36%
Hard catheter 17%
Wood, et al., Hum Reprod, 2000

20. Catheter type Pregnancy rate with different catheters Tomcat 35%
Wallace 63%
M-Wallace 69%
Schoolcraft, et al., 2003

21. Catheter type
A large volume (60μl) of transfer media and a large air interface have been shown to result in embryos which were expelled
into the cervix
on the speculum or
adherent to the catheter
Removing the air column minimized such complication

22. Avoiding any uterine contractility
Use soft catheters
Avoid touching the uterine fundus
Try to gentle manipulation

23. Uterine contractility
It was demonstrated that only 45% of embryos were present within the uterine cavity 1 h after the transfer.
Menezo, et al., Acta Europ Fertil, 1985
Stimulation of the cervix causes the release of oxytocin, thus increasing uterine contractility.

24. Touching the uterine fundus
It is a fact that if the tip of the catheter touches the uterine fundus the patients experience immediate discomfort followed by suprapubic pain
Touching the fundus with the catheter stimulated junctional zone contactions that can reduce the chances of pregnancy
Lesny, et al., Hum Reprod, 1998

25. Touching the fundus Yes 24% PR No 46% PR
Waterstone, et al., Lancet, 1991

26. Touching the fundus
Distance between the tip of the catheter and the uterine fundus
10 mm 20.6%
15 mm 31.3%
20 mm 33.3% implantation rate
Coroleu, et al., Lancet, 1991

27. Gentle manipulation
Gentle manipulation should be the rule even in introducing the speculum to avoid unnecessary pushing of the cervix.
Studies have shown that technically difficult embryo transfers are associated with reduced pregnancy rates
Sharif, et al., Hum Reprod, 1995

28. Gentle manipulation
Some authors suggest that it is preferable to wait for the release of embryos from the catheter or to wait before withdrawal of the catheter.
Wisanto, et al., Fertil Steril, 1989
It was reported no differences in the pregnancy rate between withdrawal of the catheter immediately after embryo deposit or after a 30 s wait
Martinez, et al., Hum Reprod, 2001

29. Blood
When blood was noted outside the transfer catheter, the chance of conception was reduced significantly by sixfold to sevenfold
Goudas, et al., Fertil Steril, 1998

30. Ultrasound Guidance
The full bladder required to perform transabdominal ultrasound examinations is itself helpful in straightening the cervico-uterine axis and improving pregnancy rates
Lewin et al., J Assisted Reprod Genet, 1987

31. Ultrasound Guidance
is especially helpful with the insertion of “soft” catheters. When placement is difficult, the problem may be visualized and modification of the angle between the cervix and uterus can be accomplished with manipulation of the speculum.

32. Ultrasound Guidance Better pregnancy rate No significant difference
Wood, et al., Hum Reprod, 2000
Coroleu, et al., Hum Reprod, 2000
No significant difference
Al-Shawaf, et al., J Assisted Reprod Genet, 1993
Kan, et al., Hum Reprod, 1999

33. Meta-analysis of ultrasound-guided ET
Buckett, Fertil Steril, 2003

34. Bedrest
Standing shortly after embryo transfer does not play a significant role in the final position of the embryos.
Woolcott, et al., Hum Reprod, 1998
In a study that had > 1000 cycles the results strongly suggested that bedrest was not necessary following embryo transfer
Sharif, et al., Fertil Steril, 1998

35. Protocol for ET Full bladder, US guidance
Wash cervix and lavage with culture media
Trial transfer to internal os
Wallace catheter, 30μl continious column
Gentle insertion – manipulate cervix with speculum
Examination of catheter following transfer for retained embryos

36. The goal
Atraumatic placement of the embryos 1.5 cm proximal to the fundus without pain, bleeding, trauma to the endometrium or embryos and with the absence of uterine contractions.